Is Kiffin hiring another bad move by Jerry Jones?

The Dallas Cowboys’ hiring of Monte Kiffin on Friday to run their defense seems all about reputation rather than reality.

But, then again, what else should we expect from an organization run by a man whose hold on reality – at least from a football standpoint – seems more tenuous with each passing mediocre season?

Let’s start with the obvious: Kiffin, once the NFL’s preeminent defensive mastermind, is well past his prime. On February 29, the guru of the famed Tampa Cover 2 scheme turns 73, which will be three years older than Jerry Jones.

Make no mistake: This is not to say you can’t be a senior citizen and thrive in pro football. There are some graybeards in the league that are outstanding at what they do, the best example being Pittsburgh defensive coordinator Dick LeBeau, who is 75.

But let’s not forget that the Steelers, unlike the Cowboys, have had the same defensive system in place for years. That makes LeBeau’s job much easier than the monumental task facing Kiffin, which brings us to perhaps the biggest reason why the hire is a significant gamble for Jones and Jason Garrett.

With this selection, Dallas will scrap the 3-4 front it’s employed since 2005 for the 4-3 look and zone coverage in the secondary favored by Kiffin. Never mind that most of its vital defensive cogs seem better suited for the 3-4 front and man coverage.

Think about it: The Cowboys gave a lucrative deal in free agency last spring to Brandon Carr, who is at his best in press coverage. One month later, they traded up in the draft for another press proponent, Morris Claiborne. Slot corner Orlando Scandrick is also best suited for man coverage.

And what about linchpin linebackers DeMarcus Ware and Sean Lee? Both have been outstanding in the 3-4, with Ware on the outside and Lee on the inside.

Another concern: While Kiffin was the maestro of mayhem with the Buccaneers, his performance as defensive coordinator on his son Lane’s staffs with Tennessee and Southern Cal the last four seasons can be best summed up in one word: disappointing. The Trojans finished 60th in total defense this season, yielding per-game averages of 24.3 points and 394 yards.

The firing of Rob Ryan was no surprise after Dallas made high-profile moves to upgrade its secondary but still regressed from 2011 to 2012 in several key categories, including interceptions (15 to a franchise-low seven), takeaways (plus-four to minus-11) and points allowed (347 to 400).

And let’s not forget all those times the defense had the wrong number of players on the field. Another Ryan defect: His temper resulted in an unsportsmanlike-conduct penalty in Cincinnati, an unforgiveable sin considering Garrett’s emphasis on poise.

But while Ryan had to go, Kiffin appears to be the wrong choice to replace him.

No matter what happens with the Cowboys, Kiffin’s place in NFL history is secure after he built one of the league’s all-time great defenses while Tampa Bay from 1996 through 2008. During that span, the Bucs ranked among the league’s top 10 in total defense 11 times and also finished among the top 10 in fewest points allowed 10 times.

In their Super Bowl-winning 2002 season, Tampa Bay led the NFL in total defense, fewest points allowed and interceptions, the first unit to accomplish that feat since Chicago did it 17 years earlier.

But at this moment, at his age and with the personnel he has to work with, Kiffin will be hard pressed to recapture the magic. It’s yet another questionable decision by Jones, also known as the common thread in this epic era of mediocrity for the Cowboys.